The compound 2-(3-(4-propylheptyl)morpholino)ethan-1-ol (CAS 79874-76-3) having the INN name delmopinol was disclosed for the first time by Ferrosan in EP0038785 and has the molecular structure depicted below.

Delmopinol is used in the treatment of gingivitis, prevention of plaque formation and for oral hygiene in general. It is an active component in mouth wash liquids and toothpaste for use in humans and is also used in the maintenance of oral health in animals as described in WO 2007/099302. Ferrosan in EP0038785 disclosed methods for the synthesis of 2-(3-alkylmorpholino)-ethan-1-ol derivatives and the use of their pharmaceutically acceptable salts for the treatment of the oral cavity. The described methods have several disadvantages such as the number of steps and the low yields.
WO 2007/057681 discloses a process where 2-(3-alkylmorpholino)ethan-1-ols are obtained by reaction of oxazolidin[2,3-c]morpholine with a Grignard compound R1MgX where X is a halogen selected from Cl, Br and I and R1 is an alkyl or aryl moiety.
The process disclosed in WO 2007/057681 has some disadvantages in that the synthesis of the key intermediate oxazolidin[2,3-c]morpholine has a low atom-economy and provides the compound in a modest yield. Moreover, the synthesis of oxazolidin[2,3-c]morpholine also pro-vides the by-product 2-methoxyethanol which is unwanted because of toxicity concerns and it has to be removed completely prior to the reaction with the organomagnesium reagent. Furthermore, Grignard addition to oxazolidin[2,3-c]morpholine proceeds with moderate yield.
Thus, there is a need within the field to find improved processes for producing 2-(3-(alkyl or alkenyl)morpholino)ethan-1-ols. In particular, there is a need for new methods that are safe and cost-effective and provides a high yield of 2-(3-(alkyl or alkenyl)morpholino)ethan-1-ols and are readily applicable on industrial scale.
More specifically there is the need for new methods for the preparation of delmopinol, preferably a method that is safe and cost-effective and provides a high yield of delmopinol and is readily applicable on industrial scale.